Regarding capturing of carbon dioxide, carbon dioxide capture and storage technology has recently received attention as an effective measure against global warming issues concerned on a global mass scale. In particular, a method of capturing carbon dioxide by using an aqueous solution has been studied in association with a thermal power plant and a process exhaust gas. For example, a carbon dioxide capturing apparatus is known which includes an absorption tower configured to generate a rich liquid by causing an absorption liquid to absorb a gas containing carbon dioxide, and a regeneration tower configured to heat the rich liquid discharged from the absorption tower to release the carbon dioxide and steam, separate the carbon dioxide from the steam, and return a generated lean liquid to the absorption tower.
In the step of releasing the carbon dioxide from the rich liquid, a reboiler provided adjacent to the regeneration tower circulates and heats the absorption liquid in the regeneration tower. The reboiler is supplied with a part of steam (water vapor) generated for using in a thermal power plant, a factory or the like as a heating medium. An amount of the steam supplied to the reboiler is required to be reduced.